Proof of Work — Where It All Started
Proof of Work (PoW) is the consensus mechanism that started it all. Bitcoin has used it since 2009: miners compete to solve cryptographic puzzles, the winner writes the next block and collects the reward. Simple principle, expensive to execute — and that's exactly the security mechanism.
Since Ethereum switched to PoS in 2022, Bitcoin is by far the largest PoW coin. But others exist: Litecoin, Dogecoin, Kaspa, Bitcoin Cash. Each with its own mining algorithm and economics.
Mining Economics and Hashrate
Hashrate shows how much computing power secures the network. More hashrate = more expensive to attack = more secure. But hashrate follows price: when coin price rises, mining becomes more profitable, more miners join. When price drops, weaker miners shut down.
ASIC mining (specialized hardware) vs. GPU mining is an important distinction. Bitcoin mining is ASIC-dominated — high entry costs, industrial operations. Other PoW coins are deliberately ASIC-resistant to protect smaller miners.
Energy Debate and Risks
The energy criticism of PoW is real but often oversimplified. Many mining operations use renewable energy or surplus power. Still, regulatory pressure on energy-intensive mining is growing. The halving (Bitcoin every ~4 years) cuts block rewards in half and forces miners to become efficient — or exit.
